1. Field of the Invention
This invention relates to racks for plastic T-shirt bags and more particularly to an automatic bagging system using a semi-automatic bag opening rack and bags for use therewith.
2. Description of the Prior Art
Since the mid-1980's, the use of all types of plastic shopping bags has grown explosively due to the great advantage plastic bags have over competing paper bags. Plastic bags are typically made of low or high density polyethylene. Because of high density polyethylene plastic's (HDPE's) greater resistance to stretching and deformation, HDPE plastic is generally used for making T-shirt bags. T-shirt bags have a pair of integral handles which make them easy to carry. HDPE bags are very strong and light and are much more compact than paper bags when delivered and stored. Furthermore, T-shirt bags are readily recyclable, and when not recycled, are non-toxic when incinerated and non-toxic in landfills. Most importantly, HDPE T-shirt bags are far less expensive than competing paper bags, making them the bag of choice for merchants.
Despite the many advantages HDPE T-shirt bags have over paper bags, due to their relatively thin material, unlike paper bags, they are not self-standing. In grocery stores, where quick loading of T-shirt bags is a necessary feature, it is thus desireable to support the bags, at least initially when merchandise is first begun to be loaded into the bags.
Two types of bagging racks for T-shirt bags are now widely in use. The first type has a support base, a wire rear wall, and two wire arms extending over the base. In the center top portion of the arms the wire is formed to have a section which will spread and hold the handles apart to open up the T-shirt bag. This type of bagging rack is depicted in FIGS. 1 to 4 and is further described below.
A second type of T-shirt bag bagging rack is shown in FIGS. 5 to 9. This types of rack is taught in U.S. Pat. Nos. 4,840,336 to Stroh, et al. and RE 33,264 to Baxley, et al. Both have a bottom support base and a wire rear wall. However, instead of looping the handles of the bags over the top of the support arm one at a time, these racks have sturdy wire arms extending forwardly from the back of the rack. Stacks of the T-shirt bags are loaded on the rack by passing the wire arms through relatively large apertures in the handle of the stack of bags. Although the Stroh, et al. and Baxley, et al. racks allow T-shirt bags to be somewhat more quickly readied for loading than the first type of rack, they suffer from two drawbacks. First, since these racks require relatively large apertures in the handles of the bags, the bags are weakened at their handles. Second, the checker or box boy still must grasp only the top layer of plastic of only the top bag in order to pull the top layer of plastic forward to thereby open the bag. Since T-shirt bags are made of very thin plastic, typically less than 1 mil. thick, it is sometimes difficult to grasp just the top layer of plastic and open the T-shirt bags.
A third type of bagging rack is taught in U.S. Pat. No. 4,830,317 to Kober, et al. In the Kober, et al. bagging rack, a stack of bags are hung on a stationary rear wall of the rack with their handles bent over the back of the stationary rear wall and retained by a friction bar. An L-shaped wall is hingedly mounted to a support base affixed to the stationary back wall and has a pair of adhesive rollers at the upper ends thereof; the rollers may be rotatably moved upwardly about the axis of the hinge to make contact with a small portion of the top layer of plastic of the top bag. The Kober, et al. device, however, is preferably used with bags in which the exposed side of the bags on the stack of bags is not affixed to a central tab. If attached-side bags are used, the adhesive must be quite strong in order to pull the bag open since the point of contact of the bag with the adhesive rollers is a relatively small area on the two cylindrical rollers. This presents a problem in removing bags loaded with merchandise since there is a tendency for the hinged wall to flip upwardly, thereby hindering the removal of the loaded bags. This tendency of the hinged wall to flip upwardly is particularly problematic when large items are loaded into the bags. A further complication with the Kober, et al. device is that due to the problem in achieving the precise retaining pressure needed on the handles of the stack of bags held on the backside of the stationary wall by the friction bar, it is difficult to ensure that only the handles of the top-most bag, being prepared for loading, and no other handles, are freed from the rear stationary wall. Lastly, in the Kober, et al. device even when the bag is fully loaded with merchandise, the handles of that bag are not accessible for immediate grasping by the checker or box boy. These problems with the Kober, et al. device prevent its smooth and complication-free operation. To the best of our knowledge, the Kober, et al. device has achieved no commercial success. There is thus a need for a true semi-automatic bag opening rack.